Presented at the Neonatal Society 2019 Spring Meeting.

Authors: Luke Mills, Lynda Coulter, Emma Savage, Neena Modi

Institution(s): Imperial College London, Academic Neonatal Medicine

Introduction

Better understanding of the variation in macronutrient content of human donor milk (HDM) potentiates targeted nutrition for preterm babies. This study describes the relationship of maternal age, parity, lactation time, volume of milk donated, sex, gestation, birthweight, and sex specific birthweight adjusted for gestational age z scores, with macronutrient content of HDM.

Methods

Samples from 1175 mother-infant pairs and 2966 donations to the UK North West Human Milk Bank between 2011-2017 were analysed. A stepwise multiple regression was performed using the predictor variables above on the outcome macronutrient value determined using mid infrared spectroscopy. Mean macronutrient content was also compared by gestational age, and small or appropriate for gestational age (SGA) (z score <1.28) or (AGA) (z score ≥ 1.28) categories.

Results

Mean (sd) protein, fat, carbohydrate, and calculated energy, were 0.89 (0.24) g/dl, 2.99 (0.96) g/dl, 7.09 (0.44) g/dl, and 60.37 (8.41) kcal/dl respectively. Lactation time and z score negatively predicted protein and fat. Lower gestational age predicted fat, but not protein. There were no differences between preterm gestational age categories but highest levels of protein, fat and energy were found in preterm compared to term, and SGA compared to AGA HDM in the first 3 months of lactation, with the biggest differences seen between preterm SGA and term AGA groups.

Conclusions

SGA status, as well as prematurity, may be an important determinant of macronutrient content in early lactation. As bioavailability of macronutrients from HDM is uncertain, studies evaluating growth and body composition in preterm and SGA babies fed HDM are warranted.

Corresponding author e-mail address: l.mills@imperial.ac.uk

Senior author supporting presentation on day of meeting: Neena Modi